1. Field of the Invention
This invention relates to a novel pressure sensor element which possesses the characteristic of varying in electric resistance in proportion to the magnitude of the pressure exerted thereon and is, therefore, suitable for use in the measurement of pressure in a region of high pressure.
2. Prior Art Statement
Heretofore, as instruments for the measurement of high pressure, the free-piston gauge intended as a primary pressure gauge, and the Bourdon-tube gauge and the manganin pressure gauge intended as secondary pressure gauges have been generally known.
Once the Bourdon-tube gauge is exposed to pressure of a magnitude falling above a fixed range of measurement, it is apt to cease displaying accurate measurement results or to suffer mechanical destruction. In contrast, the manganin pressure gauge has low susceptibility to these problems and, or this reason, has found wide utility. The manganin pressure gauge, however, is not necessarily easy to manufacture because the structure thereof necessitates seasoning of the manganin resistance wire.
In recent years, various automatic control systems have been developed. Most of these systems involve measurement of pressure. For the purpose of this use, it is desirable that the magnitude of the pressure be readily converted into that of electric resistance.
Where a pressure gauge is to be miniaturized enough to be conveniently incorporated in an automatic control system, the manganin pressure gauge is unsatisfactory in many points regarding dimensions of the element, magnitude of the resistance, and the rated electric power.